A Russian drone attack on Kyiv killed at least two people and injured several, sparking fires in high-rise apartment buildings and throughout the capital, Ukrainian officials said early on Sunday.

“A massive enemy drone attack on Kyiv,” Mayor Vitali Klitschko posted on the Telegram messaging app.

The scale of the overnight attack was not immediately clear. Reuters witnesses heard several blasts in what sounded like air defence systems in operation.

The state emergency service posted photos showing firefighters fighting blazes at night, including high in an apartment building.

A woman died after drone debris sparked a fire in a high-rise residential building in Dniprovskyi district, the emergency service said on Telegram, while at least 27 people were evacuated from the building.

Another person died in the Holosiivskyi district, the service said.

The United States is pushing for a peace deal between Ukraine and Russia, and hoping to agree on a partial ceasefire that would halt strikes on energy infrastructure. But both sides have been reporting continued strikes.

At least seven people were injured throughout Kyiv and emergency services were dispatched to several districts of the city where fires were reported, Klitschko said.

Two were injured and several houses damaged in the region surrounding the capital, regional Governor Mykola Kalashnik said on Telegram.

There was no immediate comment from Russia. Both sides deny targeting civilians in the three-year-long war that Russia started with its full-scale invasion on Ukraine.

Kyiv, its surrounding region and the eastern half of Ukraine were under air raid alerts for more than five hours, starting late on Saturday, according to Ukraine’s Air Force maps.